Electronic device with a wake up module distinct from a core domain

ABSTRACT

An electronic device includes an appended module coupled to a core having a standby state comprising a first power supply circuit, a first clock and a circuit that recognizes multiple vocal commands timed by the first clock. The appended module includes a second power supply circuit independent of the first power supply circuit, a second clock independent of the first clock and having a frequency lower than that of the first clock, digital unit timed by the second clock including a sound capture circuit that delivers a processed sound signal, and a processing unit configured in order, in the presence of a parameter of the processed sound signal greater than a threshold, to analyze the content of the processed sound signal and to deliver, when the content of the sound signal comprises a reference pattern, an activating signal to the core that can take it out of its standby state.

This application is a divisional of U.S. patent application Ser. No.14/852,513 entitled “Electronic Device with a Wake Up Module DistinctFrom a Core Domain,” filed Sep. 12, 2015, which application claimspriority to French Application No. 1462541, filed on Dec. 16, 2014,which applications are hereby incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present invention relate to an electronic devicecomprising a wake up module distinct from a core domain.

BACKGROUND

Electronic apparatuses, notably mobile cellular telephones, smartwatches and smart glasses, increasingly comprise modules making itpossible to carry out a voice recognition function. This functionnotably makes it possible to control the electronic apparatus vocally.

In order that the apparatus can detect vocal commands at any time, it isdesirable to monitor and detect the signals in the environment of theapparatus and notably in its sound environment.

Electronic apparatuses operating on battery power such as mobilecellular telephones are confronted with a problem related to theoptimizing of energy consumption during continuous monitoring of thesound environment searching for possible vocal commands.

In order to economize the battery of an electronic apparatus, the lattergenerally comprises a standby mode in which the electrical power supplyis maintained at the minimum in order to keep a minimum of electronicelements operating.

However, when the electronic apparatus is on standby, the latter mustcome out of its standby state before being able to carry out the processrelated to the vocal command. A user generally wishes to be able toaccess the functionalities of the apparatus quickly. It is the thereforenecessary to be able to come out of the standby state quickly in orderto respond to a vocal command by the user. One possibility is to providea reactivating button.

Similarly, when the electronic apparatus is not on standby but in anactive state, the electronic apparatus does not itself distinguish avocal command intended for it from a vocal command intended for anotherapparatus. It is the therefore necessary to provide a method fordistinguishing at what time a vocal command is intended for theapparatus.

An example of a known method for detecting the surrounding soundenvironment is the continuous audio process, or “continuous audioprocessing”, for waking a telephone. This type of method is known by theexpression “Always ON Audio” or “AON Audio”, because the audio voicerecognition circuit is kept powered and in continuous operation.

The major disadvantage of such a system is the high energy consumption,given the continuous power supply of the voice recognition circuit.

SUMMARY

The present invention relates generally to a system and method, and, inparticular embodiments, to a system and method for embodiments of theinvention relate to electronic devices comprising a processing core anda separate module intended to wake the electronic apparatus in which thedevice is installed, for example a mobile cellular telephone, by a vocalcommand.

According to one embodiment, an electronic device is proposed whosearchitecture makes it possible to minimize the energy consumption of anelectronic apparatus in which is it fitted, the apparatus furthermorecomprising a system for recognition of vocal commands.

According to one aspect, an electronic device is proposed comprising aprocessing core and an appended module coupled to the core and separatefrom the said core, the core comprising a first power supply circuit, afirst clock and a recognition circuit to recognize multiple vocalcommands timed by the first clock.

According to a general feature of this aspect, the core has a standbystate and the appended module comprises a second power supply circuitindependent of the first power supply circuit, a second clockindependent of the first clock and having a frequency lower than that ofthe first clock, a digital processing unit timed by the second clockcomprising at least a first means of capturing a first sound signal, andconfigured to deliver a processed sound signal, and a processing unitconfigured in order, in the presence of a parameter of the processedsound signal greater than a threshold, to analyze the content of theprocessed sound signal and to deliver, when the content of the soundsignal comprises a reference pattern, an activating signal to the corethat can take it out of its standby state.

As the second power supply circuit provided for powering the appendedmodule is independent of the first power supply circuit provided forpowering the core or even the rest of the electronic elements of theapparatus, the second power supply circuit can be sized and configuredto power only the appended module. Thus, the energy consumption isminimized due to the adaptation of the second power supply circuit tothe appended module.

By providing a second clock solely for the appended module with afrequency lower than the frequency of the first clock intended fortiming the core and/or the other electronic elements of an electronicapparatus comprising the device, the energy consumption of the module islow.

In fact, the lower the frequency of a clock, the lower is the energyconsumption. Thus, by timing the appended module using a low frequencyclock, the electrical energy necessary for powering the appended moduleis low notably with respect to the core whose elements are timed by aclock of higher frequency. As the necessary electrical power supply islow, the second power supply circuit can be reduced even more incomparison with the power supply circuit of the core.

The parameter of the processed sound signal can for example be theaverage level of the sound signal, or its peak factor, or again thelevel of this signal at different frequencies, without these examplesbeing limiting.

The first means of capture can be a digital or analog microphone.

As the appended module is designed for the exiting from the standby modeof the electronic apparatus in which the electronic device is installed,the processing unit can be configured to wake the electronic apparatus,notably the core of the device, solely in response to the detection of areference pattern such as a keyword.

The second clock can advantageously be less precise than the firstclock. In fact, a clock requiring less precision consumes less current.

Advantageously, the processing unit can have a standby state and can beconfigured to exit from its standby state in the presence of theprocessed sound signal level higher than the threshold.

By putting the processing unit of the appended module on standby, theenergy consumption of the appended module can be low for as long as aprocessed sound signal does not exceed a detection thresholdcorresponding for example to a sound level threshold of the processedsignal.

Thus, for example, when the processing unit is on standby, the onlyitems powered and timed by the second clock are the digital processingunit and a comparator configured to compare the sound level of theprocessed signal with a sound level threshold notably expressed indecibels. The processing unit is therefore taken out of its standbystate solely in the case where a sufficiently loud sound has beencaptured by the digital processing unit.

In this embodiment, the appended module preferably comprises a localinterconnection circuit able to couple the processing unit to the saidsecond clock in order to take it out of its standby state.

When the processing unit is on standby, it is coupled to the secondpower supply circuit, which powers it, and decoupled from the secondclock in order to reduce its electrical consumption to the minimum.

Advantageously, the digital unit can comprise a single means of capture,the processed sound signal corresponding to the sound signal captured bythe single digital means of capture.

The capture means is preferably a digital microphone positioned on theelectronic apparatus in such a way as to pick up the vocal commandscoming from the user's mouth.

As a variant, the digital unit can comprise a first capture means and atleast one supplementary capture means disposed at a location separatefrom that of the first capture means and configured to capture asupplementary sound signal, and processing unit configured to reduce theambient noise on the basis of the first sound signal and thesupplementary sound signal in order to deliver the processed soundsignal.

The first capture means can be a digital microphone disposed for exampleon the front face of a telephonic apparatus, facing the mouth of a userfor example, in order to capture the user's commands.

The supplementary capture means can be digital microphones mounted onthe rear face of the mobile cellular telephone in such a way as not toface the user's mouth. This arrangement makes it possible for thesupplementary microphones to capture the environmental sounds that canpollute the sound signal coming from the mouth of the speaker and whichcan hamper the detection of the vocal command in the signal.

In the case where several supplementary capture means are used, thesupplementary sound signals are advantageously combined with weightingcoefficients in order to obtain an equivalent supplementary sound signalwhich is then notably subtracted from the first sound signal.

According to another aspect, an electronic apparatus is providedcomprising an electronic device such as defined above.

The electronic apparatus preferably forms a mobile cellular telephone.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features of the invention will become apparent onexamination of the detailed description of an embodiment and of animplementation of the invention, that are in no way limiting, and of theappended drawings in which:

FIG. 1 is a block diagram of an electronic apparatus comprising anelectronic device according to an embodiment of the invention; and

FIG. 2 is a flowchart of a method for controlling the electronic deviceshown in FIG. 1 according to an implementation of the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 shows the block diagram of an electronic apparatus comprising anelectronic device according to an embodiment of the invention.

In the embodiment shown, the electronic apparatus 1 is a mobile cellulartelephone comprising a transceiver able to connect to or comprise anantenna 1.

The electronic apparatus 1 comprises a battery 2, a first general powersupply circuit 3 coupled to the battery 2 and to the electronic elementsof the apparatus 1, and notably to an electronic device 4.

The electronic device 4 comprises an electronic processing core 5 and anappended electronic module 6 separate from the core 5.

The core 5 comprises a first power supply circuit 7 connected at itsinput to the general power supply circuit 3, a first clock 8 having afirst timing frequency and a circuit 9 to recognize multiple vocalcommands timed by the signal of the first clock 8 and powered by thefirst power supply circuit 7. The circuit 9 of recognition of multiplevocal commands notably comprises a microprocessor configured torecognize a plurality of different vocal commands and to deliver thesecommands to a microprocessor of the apparatus 1 in order to control thefunctions related to the commands.

The appended module 6 comprises a second power supply circuit 10connected at its input to the general power supply circuit 3. The secondpower supply circuit 10 is independent from the first power supplycircuit 7 of the core 5.

The appended module 6 also comprises a second clock 11 that isindependent from the first clock 8 and has a second timing frequencylower than the first timing frequency of the first clock 8 of the core5. The lower the frequency of a clock, the less energy this clockconsumes. In fact, the second clock 11, and therefore the appendedmodule 6, consumes less electrical energy than the core 5 whenoperating.

The appended module 6 furthermore comprises a digital processing unit 12powered by the second power supply circuit 10 and timed by the secondclock 11. The digital processing unit 12 comprises a first digitalmicrophone 13 fixed on a front face of the apparatus 1 in such a way asto face the mouth of a user and to receive the user's vocal commands.The digital processing unit 12 also comprises a second digitalmicrophone 14 fixed on a rear face of the apparatus 1 in such a way asnot to face the mouth of the user and to capture the environmentalnoise.

The microphones 13 and 14 can also be analog microphones, each coupledat its output to an analog-to-digital converter.

The digital processing unit 12 comprises processing unit 15 that is ableto receive the sound signal captured by each of the two digitalmicrophones 13 and 14 and to deliver a processed sound signal free fromthe ambient noise as much as possible.

In the case of a digital processing unit 12 comprising only a singledigital microphone, the processed signal delivered by the digitalprocessing unit corresponds to the sound signal captured by the singledigital microphone.

In the embodiment shown, the processing unit 15 is configured to delivera processed sound signal whose ambient noise has been reduced or eveneliminated, from the sound signal captured by the first digitalmicrophone 13 placed on the front face of the apparatus 1 and from thesound signal captured by the second digital microphone 14 placed on therear face of the apparatus 1 for capturing the ambient noise. Theprocessing unit 15, notably comprising a subtractor, thus delivers aprocessed sound signal cleansed of the ambient noise and in which thereessentially remains the vocal command of the user if there is one.

The digital processing unit 12 thus continuously records low frequencysound via the two digital microphones 12 and 13. The processing unit 15of the digital processing unit 12 comprises an input stage fordecimation of the sound signals received from the digital microphones 13and 14 in order to create samples of sound signals to process andpossibly to analyze.

The appended module 6 furthermore comprises a comparator 16 and aprocessing unit 17, for example a microcontroller, configured to analyzethe content of the processed sound signal.

The input of the comparator 16 is connected to the output of the digitalprocessing unit 12 in order to receive the processed sound signal, andthe output of the comparator 16 is connected to a control input of theprocessing unit 17. The comparator 16 compares for example the soundlevel of the processed sound signal with a detection thresholdcorresponding to a sound level in decibels.

The processing unit 17 has a standby state in which its clock input isblocked so that the processing unit is no longer timed by the signal ofthe second clock and does not operate. The processing unit 17nevertheless remains powered by the second power supply circuit 10during its standby state.

When the processed sound signal is greater than the threshold, thecomparator 16 delivers an activation signal to the processing unit 17.The activation signal commands the unblocking of the clock input of theprocessing unit 17. The exit from standby of the processing unit 17 istherefore characterized by a resumption of its timing by the signal ofthe second clock 11.

At the same time as the activation signal of the processing unit 17, thecomparator also transmits the processed sound signal for analysis by theprocessing unit 17.

As a variant, the digital processing unit 12 could deliver the processedsound signal simultaneously to the comparator 16 and to the processingunit 17, the comparator 16 then only delivering the activation signal ofthe processing unit 17 when the sound level of the processed soundsignal is greater than the detection threshold. If the processed soundsignal has a sound level lower than the threshold, the activation signalis not delivered, which results in the processing unit not exiting fromits standby state and the processed sound signal is not analyzed by theprocessing unit 17.

In another variant, the comparator 16 can deliver the activation signalto a local interconnection circuit comprised in the appended module 6only, the processing unit 17 and the second clock 11 being connected viathe interconnection circuit.

When the processing unit 17 has exited from its standby state, itanalyzes the received processed sound signal. The analysis comprises asearch for a reference pattern corresponding for example to the soundsignal of a keyword for waking the apparatus 1. The search is carriedout conventionally for example by frequency comparison of the soundsignal with the frequency signature of the reference pattern.

If the reference pattern is detected, the processing unit 17 delivers asignal for reactivation of the electronic apparatus 1 and notably of thecore 5.

The electronic device 4 comprises an interconnection circuit 18 makingit possible to connect the output of the processing unit 17 of theappended module 6 to the processing unit 9 of the core 5 to command theactivation of the core 5.

FIG. 2 shows a flowchart of a method for controlling the electronicdevice 4 shown in FIG. 1 according to an implementation of theinvention.

In a first step 100, sound is captured continuously by means of the twodigital microphones 13 and 14.

In a next step 102, the captured sound signals are decimated in order toobtain successive samples of constant size.

Then, in a step 104, a processing of the sound signal is carried out inorder to reduce the ambient noise on the basis of the sample of thesound signal captured by the second digital microphone 14 and thecorresponding sample of the sound signal captured by the first digitalmicrophone 13. The processed sound signal is thus cleansed of theambient noise and essentially comprises the vocal command of the user itthere is one.

In a next step 106, the processed sound signal is then compared with athreshold for activation of the processing unit 17. If the sound levelof the processed sound signal is below the activation threshold, thereis a return to the initial step 110 in order to analyze the next sample.

On the other hand, if the sound level of the processed sound signal isabove the activation threshold, the processing unit 17 is woken in astep 108. The waking, that is to say the reactivation, of the processingunit 17 is carried out by a resumption of the timing of the processingunit 17 by the signal of the second clock 11.

In a next step 110, the processing unit 17 searches for the presence ofthe reference pattern in the processed sound signal.

If the reference pattern is not detected in the processed sound signal,the processing unit 17 is switched back into its standby state and stopsbeing timed by the second clock 11, and there is a return to the initialstep 100.

On the other hand, if the reference pattern is detected in the processedsound signal, the processing unit 17 delivers, in a step 114, a signalfor the activation of the core 5. The core 5 is then activated as wellas the recognition circuit.

This device makes it possible to have an electronic apparatus configuredto receive a vocal command to wake the apparatus before receiving vocalcommands to request the apparatus to carry out certain specificfunctions. Thus, to request the apparatus, whilst on standby, to carryout a function, it suffices to give a unique vocal command followed by avocal command to carry out the desired function. This can be done forexample on the basis of a waking keyword and a request phrase for thefunction to be carried out.

The architecture of the electronic device furthermore makes it possibleto carry out these functions whilst minimizing the energy consumption ofthe apparatus, by allowing a reduced operation on standby neverthelessauthorizing the reception of a vocal wake command and thus increasingthe service life of the electronic apparatus between two recharges.

What is claimed is:
 1. A device, comprising: a processing core having aprocessing core active state and a processing core standby state,wherein the processing core comprises: a first power supply circuit; afirst clock; and a sound recognition circuit configured to recognizemultiple vocal commands timed by the first clock; an appended circuitcoupled to the processing core and separate from the processing core,the appended circuit having an appended circuit active state and anappended circuit standby state, wherein the appended circuit comprises:a second power supply circuit independent from the first power supplycircuit; a second clock that does not draw a clock signal from or supplythe clock signal to the first clock, the second clock having a frequencylower than that of the first clock; a digital processing unit comprisinga microphone and timed by the second clock, the digital processing unitbeing configured to capture a first sound signal using the microphoneand to generate a processed sound signal; and a processing unitconfigured to analyze content of the processed sound signal when theappended circuit is in the appended circuit active state and, when thecontent of the processed sound signal comprises a reference pattern, todeliver an activating signal to the processing core that can take theprocessing core out of the processing core standby state.
 2. The deviceof claim 1, wherein the digital processing unit further comprises asecond microphone spaced apart from the microphone, wherein the secondmicrophone is configured to capture ambient noise.
 3. The device ofclaim 2, wherein the processed sound signal comprises the first soundsignal cleansed of the ambient noise.
 4. The device of claim 3, whereinthe content of the processed sound signal is analyzed based upon thefirst sound signal cleansed of the ambient noise.
 5. The device of claim1, wherein the processing unit is configured to be powered by the secondpower supply circuit when the appended circuit is in the appendedcircuit active state and when the appended circuit is in the appendedcircuit standby state.
 6. The device of claim 5, wherein a clock inputof the processing unit is configured to receive the second clock whenthe appended circuit is in the appended circuit active state, andwherein the clock input of the processing unit is configured to beblocked from receiving the second clock when the appended circuit is inthe appended circuit standby state.
 7. The device of claim 1, whereinthe appended circuit further comprises: a comparator coupled between thedigital processing unit and the processing unit, the comparator beingconfigured to modulate coupling of a clock input of the processing unitto the second clock in response to a comparison of a parameter of theprocessed sound signal to a threshold.
 8. The device of claim 7, whereinthe comparator is configured to cause the clock input of the processingunit to be coupled to the second clock in response to the parameter ofthe processed sound signal being greater than the threshold.
 9. Thedevice of claim 7, wherein the comparator is configured to compare theparameter of the processed sound signal to the threshold when theappended circuit is in the appended circuit standby state.
 10. A method,comprising: capturing a sound signal; processing the sound signal;comparing the processed sound signal with a threshold for activation todetermine that a signal level of the processed sound signal exceeds thethreshold; waking up a processing unit from a standby state; using theprocessing unit to determine that a reference pattern is detected in theprocessed sound signal; and delivering a signal from the processing unitto activate a core that is separate from the processing unit.
 11. Themethod according to claim 10, wherein the sound signal comprises a keyword followed by a function request; wherein the reference pattern isrelated to the key word; and wherein the method further comprises thecore performing a function indicated by the function request.
 12. Themethod according to claim 10, wherein the processing unit receives powerfrom a first power supply circuit and wherein the core receives powerfrom a second power supply circuit that is independent of the firstpower supply circuit.
 13. The method according to claim 10, wherein theprocessing unit is clocked with a first clock signal at a firstfrequency and wherein the core is clocked with a second clock signal ata second frequency that is higher than the first clock frequency. 14.The method according to claim 13, wherein waking up the processing unitcomprises providing a first clock signal to the processing unit.
 15. Themethod according to claim 10, wherein capturing the sound signalcomprises continuously capturing sound signals using first and seconddigital microphones.
 16. The method according to claim 15, whereinprocessing the sound signal comprises decimating the captured sound toobtain successive samples and processing the decimated sound signals inorder to reduce ambient noise based on samples of the sound signalscaptured by the first digital microphone and corresponding samples ofthe sound signals captured by the second digital microphone.
 17. Amethod, comprising: continuously capturing sound signals using first andsecond digital microphones; decimating the captured sound signals aredecimated in order to obtain successive samples of constant sizeprocessing the decimated sound signals in order to reduce ambient noisebased on samples of the sound signals captured by the first digitalmicrophone and corresponding samples of the sound signals captured bythe second digital microphone; comparing the processed sound signalswith a threshold for activation to determine whether or not a signallevel of the processed sound signals exceeds the threshold; if thesignal level does not exceed the threshold, returning to the step ofcontinuously capturing sound signals; if the signal level exceeds thethreshold, waking up a processing unit from a standby state; using theprocessing unit to determine whether or not a reference pattern isdetected in the processed sound signals; if the reference pattern is notdetected in the processed sound signals, switching the processing unitback into standby state; and if the reference pattern is detected in theprocessed sound signals, delivering a signal from the processing unit toactivate a core that is separate from the processing unit.
 18. Themethod according to claim 17, wherein the processed sound signalscomprises a voice command.
 19. The method according to claim 18, whereinthe voice command comprises a keyword followed by a request phrase for afunction be carried out.
 20. The method according to claim 17, whereinwaking up the processing unit comprises providing a clock signal to theprocessing unit and where in switching the processing unit back into thestandby state comprises ceasing to provide a clock signal to theprocessing unit.
 21. A method of operating a mobile communicationdevice, the method comprising: capturing a sound signal that includes akey word and a function request; processing the captured sound signal toremove noise from the captured sound signal; determining that a signallevel of the processed sound signal exceeds a threshold; waking up aprocessing unit from a standby state in response to determining that thesignal level of the processed sound signal exceeds the threshold,wherein the processing unit receives power from a first power supplycircuit; using the processing unit to determine that the key word ispresent in the processed sound signal; activating a core in response todetermining that the key word is present in the processed sound signal,wherein the core receives power from a second power supply circuit thatis independent of the first power supply circuit; and using the core toperform a function based on the function request.
 22. The methodaccording to claim 21, wherein capturing the sound signal comprisescontinuously capturing sound signals using first and second digitalmicrophones.
 23. The method according to claim 22, wherein processingthe sound signal comprises decimating the captured sound signal andprocessing the decimated sound signal in order to reduce ambient noisebased on samples of the sound signals captured by the first digitalmicrophone and corresponding samples of the sound signals captured bythe second digital microphone.
 24. The method according to claim 21,wherein the processing unit receives power from a first power supplycircuit and wherein the core receives power from a second power supplycircuit that is independent of the first power supply circuit.
 25. Themethod according to claim 21, wherein the processing unit is clockedwith a first clock signal at a first frequency and wherein the core isclocked with a second clock signal at a second frequency that is higherthan the first frequency.